Lamp fixture and fluorescent lamp therefor

ABSTRACT

A lamp fixture and a complementary fluorescent lamp having a tube with three right angle bends defining a pair of mutually perpendicular end portions and a pair of mutually perpendicular intermediate portions paralleling the end portions respectively. One tube end portion and its parallel intermediate tube portions have substantially equal lengths. The remaining tube end portion has a length approximately one half that of its parallel intermediate tube portion such that each lamp has a G shape. A pair of such lamps may be arranged in side-by-side inverted relation with the shorter end portions of the lamp tubes disposed end-to-end and electrically connected through their adjacent end terminals to form a fluorescent lamp assembly having a generally figure-eight configuration. The complementary lighting fixture comprises a reflector housing containing and conforming in shape to the fluorescent lamp assembly.

United States Patent [191 Ebin et a1.

LAMP FIXTURE AND FLUORESCENT LAMP THEREFOR Inventors: Joseph A. Ebin, Los Angeles; John W. Logan, Hollywood, both of Calif.

Assignee: Lockheed Aircraft Corporation,

Burbank, Calif.

Filed: Sept. 25, 1972 Appl. No.: 291,541

Int. Cl. ..H05b 33/02 Field of Search ..240/51.12; 313/220 References Cited UNITED STATES PATENTS Shelton ..240/51.12 X Griggs ..240/51.l2 UX May 22, 1973 [5 7] ABSTRACT A lamp fixture and a complementary fluorescent lamp having a tube with three right angle bends defining a pair of mutually perpendicular end portions and a pair of mutually perpendicular intermediate portions paralleling the end portions respectively. One tube end portion and its parallel intermediate tube portions have substantially equal lengths. The remaining tube end portion has a length approximately one half that of its parallel intermediate tube portion such that each lamp has a G shape. A pair of such lamps may be arranged in side-by-side inverted relation with the shorter end portions of the lamp tubes disposed end-to-end and electrically connected through their adjacent end terminals to form a fluorescent lamp assembly having a generally figure-eight configuration. The complementary lighting fixture comprises a reflector housing containing and conforming in shape to the fluorescent lamp assembly.

12 Claims, 5 Drawing Figures PATENTEU MAY 2 2 I975 SHEET 1 [IF 2 PATENTEU W22 I973.

SHEET 2 UF 2 LAMP FIXTURE AND FLUORESCENT. LAMP THEREFOR This application is a division of copending application Ser. No. 78,093 filed Oct. 5, 1970, both of which are of common assignee.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates generally to the field of interior lighting and more particularly to a lighting system comprising a fluorescent lamp of novel configuration and a complementary lighting fixture therefor.

2. Discussion of the Prior Art As will appear from the ensuing description, the present fluorescent lamp and lighting fixture are capable of use in a wide variety of interior lighting applications.

Architectural interiors are commonly illuminated by direct and indirect light from fluorescent and incandescent lighting fixtures. One of the more widely used lighting fixture of this kind is disclosed in US. Pat. No. 3,319,059 and has a plurality of contiguous rectangular reflector housings which may be arranged in the general shape of a figure eight or other cellular patterns. This housing includes multiple spaced orthogonal longitudinal reflector channels interconnected at their ends. These channels are open through one side of the housing and contain fluorescent tubes. The open sides of the channels are commonly closed by transparent or translucent dust covers.

In use, a number of the fluorescent lighting fixtures are suspended from the ceiling in rows extending lengthwise and crosswise of the room. The fixtures are installed in such a way that the reflector channels of the lamp housing open upwardly toward the ceiling which constitutes a diffuse light reflector. Accordingly, light from the fluorescent lamps of the lighting fixtures is first directed upwardly to the ceiling, which then redirects the light, by diffuse reflection, back down into the room.

Prior art fluorescent lighting fixtures of this general kind possess certain disadvantages which the present invention overcomes. One of these disadvantages resides in the fact that each lighting fixture requires a number of separate straight fluorescent lamps or tubes, one in each of the longitudinal and transverse reflector channels of the fixture lamp housing. These fluorescent tubes may, in certain instances, be of differing length with the result that a supply of tubes of differing length must be maintained in stock for replacement purposes. This, of course, complicates the logistic task of maintaining the proper stock of fluorescent tubes on hand and the attendant bookkeeping procedures. Moreover, servicing of a single lighting fixture may involve the replacement of a number of the separate fluorescent tubes which is a tedious and time consuming task.

Another disadvantage of the existing fluorescent lighting fixtures is that each fluorescent tube requires two electrical receptacles. As a consequence, a figureeight arrangement employing the fixture of the aforementioned prior art patent may require fourteen receptacles. This large number of receptacles adds substantially to the cost of the fixture. Moreover, the multiplicity of tubes and receptacles required inherently increases the complexity of manufacturing and installing the lighting fixtures, and hence also the task of servicing them, and reduces the reliability of the lighting system.

SUMMARY OF THE INVENTION The present invention provides an improved lighting system of the class described employing a novel fluorescent lamp or tube, which avoids the above and other disadvantages of the existing fixtures. By way of example, the invention will be described as applied to the interior lighting of passenger compartments of commercial aircraft. The lighting system of the invention comprises a reflector housing having a pair of spaced parallel longitudinal reflector channels and three transverse reflector channels normal to and extending between the centers and ends of the longitudinal channels. These channels define two generally rectangular reflector channel sections having as a common channel the central transverse reflector channel which extends between the centers of the longitudinal reflector channels.

Contained within these rectangular reflector channel sections are two fluorescent lamps of unique configuration resembling the letter G. The tubular envelope of each fluorescent lamp has three right-angle bends which define a pair of mutually perpendicular intermediate tube sections parallel to the end tube sections, respectively, such that the tube sections lie along the four sides of a rectangle. One end tube section and its parallel intermediate tube section have approximately the same length. The length of the remaining end tube section is approximately one half that of its parallel intermediate tube section. At the ends of the tube are electrical terminals across which a voltage is applied to illuminate the tube.

Two such fluorescent tubes are placed in mutually inverted relation within the two rectangular channel sections of the reflector housing in a manner such that the shorter end sections of the tubes are disposed endto-end within the common center transverse channel. Mounted within the center channel between the adjacent ends of the tubes is a receptacle for receiving and electrically contacting the tubeend terminals. When thus mounted, the two tubes form a unitary fluorescent lamp or tube assembly having a figure-eight configuration matching that of the reflector housing. The two outer end terminals of this tube assembly engage electrical receptacles within the reflector housing which are connected to a source of suitable operating potential to illuminate the tube assembly. It will be understood that the source of operating potential may comprise a ballast or other conventional and well-known apparatus useful in the operation of fluorescent or gasdischarge lamps.

When used for aircraft lighting, the present lighting fixture is installed so as to direct light upwardly to a ceiling reflector which then redirects the light back down to passenger compartment by diffuse reflection. According to one feature of the invention, a reflector is mounted within the center transverse reflector channel of the reflector housing below the adjacent ends and intervening coupling receptacle of the two fluorescent tubes. This reflector reflects the light from the adjacent tube ends through the open side of the reflector channel in such a way as to provide generally uniform illumination opposite the region occupied by the coupling receptacle and hence along the entire length of the channel. This feature, coupled with the feature that the fluorescent tubes extend around the several corners of the reflector housing enables the present lighting fixture to provide generally uniform, shadowless illumination, without dark regions, over virtually the entire area of the ceiling or reflective surface. According to another feature of the invention, the reflector housing is hinged along one longitudinal side to the ceiling, or adjacent structure, such that the housing may be swung down to replace the fluorescent tubes. The other side of the housing is attached with positive locking quick disconnect latches. The transparent or translucent dust cover of the housing may be resiliently flexible so as to permit easy separation of the cover from the housing and thereby provide access to the fluorescent tubes for replacement purposes.

Other important features of the lighting system reside in the fact that it requires a minimal number of electrical receptacles for connection to the external electrical supply, as compared with prior systems, thus simplifying and reducing the cost of the fixture and enhancing its reliability, and in the fact that the two fluorescent tubes of the fixture are identical and are merely inverted relative to one another when installed in the reflector housing, thus reducing the number of spare tubes which must be maintained in stock for replacement purposes and simplifying the attendant bookkeeping and storage procedures.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of an aircraft lighting installation embodying fluorescent lighting fixtures according to the invention;

FIG. 2 is an enlarged perspective'view of one of the lighting fixtures, with a portion of the fixture dust cover retracted to partially expose the fluorescent tubes of the fixture;

FIG. 3 is an enlarged top plane view of the lighting fixture with a portion of the dust cover broken away;

FIG. 4 is a section taken on line 44 in FIG. 3; and

FIG. 5 is an enlarged section taken on line 5-5 in FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT As noted earlier, the lighting system of the invention may be utilized in any desired lighting installation but is particularly useful for lighting the passenger compartments of commercial aircraft. FIG. 1 illustrates such an aircraft lighting installation embodying a number of the present lighting fixtures 10. These fixtures are suspended below the reflective ceiling of the aircraft which serves as reflectors 12 in passenger compartment l4 and are arranged in rows extending laterally-and lengthwise of the compartment. Between the adjacent fixtures in the lateral fixture rows are longitudinal beams 16 containing electrical wires (not shown) for conveying electrical current to the fixtures. As will be explained presently, the fixtures are hinged to the beams 16 such that the fixtures may be swung down to their vertical positions of FIG. 1 for cleaning and replacement of their fluorescent tubes.

The several lighting fixtures 10 of the lighting installation are identical so that a description of one will suffice for all. Referring particularly to FIGS. 2-4, the lighting fixture 10 comprises a reflector body 18 having a generally figure-eight configuration. The body comprises a pair of spaced parallel longitudinal reflector channels 20 and three transverse reflector channels 22 extending between the centers and ends, respectively,

of the longitudinal channels. The reflector body 18 thus manner shown in FIG. 2. It will be observed in this figure that the dust cover is split into two sections which are hinged at 27 to the outer walls of the longitudinal channels 20 in such a way that each half of the cover may be retracted to uncover the underlying portions of the body channels 20, 22. The hinge means 27 required for this hinging action may be actual hinges or integral plastic hinges incorporated into the cover.

Within the reflector body 18 is a fluorescent lamp assembly 28 whose arrangement constitutes an important feature of the invention. This lamp assembly is composed of two identical fluorescent lamps 30 of novel shape resembling the figure G. Thus each lamp 30 has an envelope tube 32 with three right angle bends 34. These bends provide the tube with mutually perpendicular end tube sections 36, 38 and mutually perpendicular intermediate tube sections 40, 42. The intermediate tube section 40, 42 parallel the end tube sections 36, 38, respectively. End tube section 36 and its parallel intermediate tube section 40 have approximately the same length. The end tube section 38, on the other hand, has a length approximately one half that of its parallel intermediate tube section 42. On the ends of the tube 32 are terminals 44, 46 through which the tube is energized.

The two fluorescent lamps 30 are shaped and sized to fit within the two rectangular channel sections 24 of the reflector body 18 in the manner best seen in FIG. 3. It will be observed in this figure that the two lamps are inverted relative to one another about an axis normal to the lamp tube sections 38, 42 and placed in the rectangular channel sections 24 with the shorter end sections 38 of the two lamps disposed in coaxial end to end relation within the common center transverse channel 22.

Mounted within a partition 48 extending across the center channel 22 between the adjacent ends of the fluorescent lamps 30 is an electrical receptacle 50 which receives and electrically connects the terminals 44 at the lamp ends. The electrical terminals 46 at the opposite ends of the lamps are received in electrical receptacles 52 mounted in partitions extending across the reflector channels 20 and adapted for connection to an electrical power supply for energizing the lamps. Additional lamp supports 54 are provided along the lamps for engaging and supporting the lamp tubes 32 in centered relation within the reflector housing channels 20, 22, as shown.

From the above description, it will be understood that the fluorescent lamps 30 of the lamp assembly 28 are energized by connecting their terminals receptacles 52 to a suitable electrical power source. When thus energized, the lamps glow or fluoresce to emit light through the transparent or translucent dust cover 26 of the lighting fixture. The inner wall surfaces of the reflector channels 20, 22 are reflective surfaces which reflect light from the lamps toward the dust cover to increase the illumination emitted by the fixture.

As noted earlier, in the exemplary aircraft lighting installation shown in the drawings, a number of the present lighting fixtures are supported below the ceiling reflector 12 in rows extending laterally and longitudinally of the passenger compartment. The lighting fixtures are installed with their dust covers 26 uppermost and facing the ceiling which serves as a reflector. Accordingly, light from the fixtures is transmitted upwardly to the ceiling and is then reflected back to the passenger compartment by diffuse reflection to provide indirect illumination for the compartment. Referring particularly to FIGS. 1 and 5, it will be seen that each lighting fixture is attached by hinges 56 along one of its longitudinal reflector channels to the adjacent ceiling beam 16. Each fixture may be lowered on its hinge axis between its normal horizontal lighting position of FIG. 5 and the vertical position of FIG. 1. When in the vertical position, each fixture is accessible for cleaning and replacement of its fluorescent lamps 30 by opening of its dust cover 26 from the fixture body 18 in the manner shown in FIG. 2. Each lighting fixture is supported by suitable hinges and hangers 58 in its normal horizontal lighting position by means of which it may be-released to drop the fixture to its lowered cleaning and lamp replacement position.

As noted earlier, the two fluorescent lamps 30 of each lighting fixture are connected, via receptacle 52, to a suitable electrical power source by means of electrical wiring (not shown) within the ceiling beams 16.

An important advantage of the present lighting system concerns the uniform illumination furnished thereby. It is significant to note that the fluorescent lamps 30 extend around the corners of the reflector body 18 and thus provide continuous uniform illumination at the corners. According to a feature of the invention, a reflector 60 is mounted within the center transverse reflector channel 22 below the receptacle 50 which connects the adjacent lamp terminals 44. This reflector has two reflector plates 62 which extend, in oblique angular relation to one another and to the lamp tubes 32, from the coupling receptacle 50 outwardly under the adjacent tube ends. As shown in FIG. 4, the reflector is thus arranged to reflect light from the adjacent tube ends to the region of the reflective ceiling 12 over the receptacle. Accordingly, generally uniform illumination is provided along the entire length of the center reflector channel. The proximity of the end receptacle 52 of each lamp to the adjacent bend in the other lamp provides generally uniform illumination along the longitudinal reflector channels 20. The lamps being continuous along the outer transverse reflector channels, obviously provide uniform illumination along these latter channels.

In conclusion, it is evident that while the transverse reflector channels 22 extend between the centers and ends of the longitudinal reflector channels 20, such that the reflector housing 18 is designed to receive only two lamps 30, the housing may be extended to receive additional lamps.

What is claimed is:

1. A fluorescent lighting system comprising:

reflector means including a pair of spaced parallel longitudinal reflector channels and three transverse reflector channels normal to and extending between said longitudinal channels, whereby said channels define two rectangular channel sections having the center transverse channel as a common channel;

a pair of fluorescent lamps within said rectangular channel sections, respectively, each comprising a tubular envelope having three right angle bends defining first and second mutually perpendicular end tube sections and first and second mutually perpendicular intermediate tube sections paralleling said first and second end sections, respectively, said first end and intermediate tube sections having substantially equal lengths and said second end tube section having a length approximately one half that of said second intermediate tube section, said lamps being positioned in mutually inverted relation within said rectangular channel sections, respectively, such that said second end tube sections are disposed in coaxial end-toend relation within said common center transverse channel, and said reflector channels opening to one side of said reflector means and having inner reflecting surfaces for reflecting light from said lamps through the open sides of said channels; and,

electrical terminal means at the ends of said tubes.

2. A lighting system as defined in claim 1 including:

means electrically connecting the end terminals on said second end tube sections whereby said lamps may be illuminated by connecting their remaining end terminals to an electrical source.

3. A lighting system as defined in claim 1 including:

a reflector positioned below said connecting means and the adjacent ends of said tubes for reflecting the light emitted from said adjacent tube ends through the open side of said center transverse channel in a manner to provide generally uniform illumination along the entire length of said center channel section.

4. A lighting system as defined in claim 1 including:

a light-transmitting dust cover over said open channel sides having portions which are hinged to permit access to said lamps.

5. A lighting system as defined in claim 1 wherein:

said transverse channels extend between the ends and centers of said longitudinal channels.

6. A lighting system as defined in claim 1 including:

a reflector positioned below said connecting means and the adjacent ends of saidtubes for reflecting the light emitted from said adjacent tube ends through the open side of said center transverse channel in a manner to provide generally uniform illumination along the entire length of said center channel section; and

a light-transmitting dust cover over said open channel sides having portions which are hinged to permitaccess to said lamps.

7. A lighting system as defined in claim 1 wherein:

said transverse channels extend. between the ends and centers of said longitudinal channels.

8. A lighting installation comprising:

a reflective ceiling;

a fluorescent lighting fixture comprising a reflector housing of generally figure-eight configuration including a pair of spaced parallel longitudinal reflector channels and three transverse reflector channels normal to and extending between said longitudinal channels, whereby said channels define two rectangular channel sections having the center transverse channel as a common channel; pair of fluorescent lamps within said rectangular channel sections, respectively, each comprising a tubular envelope having three right angle bends defining first and second mutually perpendicular end tube sections and first and second mutually perpendicular intermediate tube sections paralleling said first and second end sections, respectively, said first end and intermediate tube sections having substantially equal lengths and said second end tube section having a length approximately one half that of said second intermediate tube section, said lamps being positioned in mutually inverted relation within said rectangular channel sections, respectively, such that said second end tube sections are disposed in coaxial end-to-end relation within said common center transverse channel, and said reflector channels opening to one side of said housing and having inner reflecting surfaces for reflecting light from said lamps through the open sides of said channels; electrical terminals on the ends of said tube; and, means supporting said fixture below and in spaced relation to said reflective ceiling with said reflector channels opening upwardly toward said ceiling. 9. A lighting installation as defined in claim 8 wherein said lighting fixture includes:

first means electrically connecting the end terminals on said second end tube sections in common; and, second means for connecting the remaining end terminals in common.

10. A lighting installation as defined in claim 8 wherein said lighting fixture includes:

a reflector positioned below said connecting means and the adjacent ends of said tubes for reflecting through the open side of said center transverse channel the light emitted from said adjacent tube ends in a manner to provide generally uniform illumination along the entire length of said center channel section.

11. A lighting installation as defined in claim 8 wherein:

said fixture supporting means comprise hinge means about which said fixture is rotatable to a lowered vertical position; and

said fixture includes a light-transmitting dust cover over said open channel sides which are hinged to permit access to said lamps.

12. A lighting installation as defined in claim 11 wherein said lighting fixture includes:

first means electrically connecting the end terminals on said second end tube sections in common;

second means for connecting the remaining end terminals in common; and,

a reflector positioned below said connecting means and the adjacent ends of said tubes for reflecting through the open side of said center transverse channel the light emitted from said adjacent tube ends in a manner to provide generally uniform illumination along the entire length of said center channel section. 

1. A fluorescent lighting system comprising: reflector means including a pair of spaced parallel longitudinal reflector channels and three transverse reflector channels normal to and extending between said longitudinal channels, whereby said channels define two rectangular channel sections having the center transverse channel as a common channel; a pair of fluorescent lamps within said rectangular channel sections, respectively, each comprising a tubular envelope having three right angle bends defining first and second mutually perpendicular end tube sections and first and second mutually perpendicular intermediate tube sections paralleling said first and second end sections, respectively, said first end and intermediate tube sections having substantially equal lengths and said second end tube section having a length approximately one half that of said second intermediate tube section, said lamps being positioned in mutually inverted relation within said rectangular channel sections, respectively, such that said second end tube sections are disposed in coaxial end-to-end relation within said common center transverse channel, and said reflector channels opening to one side of said reflector means and having inner reflecting surfaces for reflecting light from said lamps through the open sides of said channels; and, electrical terminal means at the ends of said tubes.
 2. A lighting system as defined in claim 1 including: means electrically connecting the end terminals on said second end tube sections whereby said lamps may be illuminated by connecting their remaining end terminals to an electrical source.
 3. A lighting system as defined in claim 1 including: a reflector positioned below said connecting means and the adjacent ends of said tubes for reflecting the light emitted from said adjacent tube ends through the open side of said center transverse channel in a manner to provide generally uniform illumination along the entire length of said center channel section.
 4. A lighting system as defined in claim 1 including: a light-transmitting dust cover over said open channel sides having portions which are hinged to permit access to said lamps.
 5. A lighting system as defined in claim 1 wherein: said transverse channels extend between the ends and centers of said longitudinal channels.
 6. A lighting system as defined in claim 1 including: a reflector positioned below said connecting means and the adjacent ends of said tubes for reflecting the light emitted from said adjacent tube ends through the open side of said center transverse channel in a manner to provide generally uniform illumination along the entire length of said center channel section; and a light-transmitting dust cover over said open channel sides having portions which are hinged to permit access to said lamps.
 7. A lighting system as defined in claim 1 wherein: said transverse channels extend between the ends and centers of said longitudinal channels.
 8. A lighting installation comprising: a reflective ceiling; a fluorescent lighting fixture comprising a reflector housing of generally figure-eight configuration including a pair of spaced parallel longitudinal reflector channels and three transverse reflector channels normal to and extending between said longitudinal channels, whereby said channels define two rectangular channel sections having the center transverse channel as a common channel; a pair of fluorescent lamps within said rectangular channel sections, respectively, each comprising a tubular envelope having three right angle bends defining first and second mutually perpendicular end tube sections and first and second mutually perpendicular intermediate tube sections paralleling said first and second end sections, respectively, said first end and intermediate tube sections having substantially equal lengths and said second end tube section having a length approximately one half that of said second intermediate tube section, said lamps being positioned in mutually inverted relation within said rectangular channel sections, respectively, such that said second end tube sections are disposed in coaxial end-to-end relation within said common center transverse channel, and said reflector channels opening to one side of said housing and having inner reflecting surfaces for reflecting light from said lamps through the open sides of said channels; electrical terminals on the ends of said tube; and, means supporting said fixture below and in spaced relation to said reflective ceiling with said reflector channels opening upwardly toward said ceiling.
 9. A lighting installation as defined in claim 8 wherein said lighting fixture includes: first means electrically connecting the end terminals on said second end tube sections in common; and, second means for connecting the remaining end terminals in common.
 10. A lighting installation as defined in claim 8 wherein said lighting fixture includes: a reflector positioned below said connecting means and the adjacent ends of said tubes for reflecting through the open side of said center transverse channel the light emitted from said adjacent tube ends in a manner to provide generally uniform illumination along the entire length of said center channel section.
 11. A lighting installation as defined in claim 8 wherein: said fixture supporting means comprise hinge means about which said fixture is rotatable to a lowered vertical position; and said fixture includes a light-transmitting dust cover over said open channel sides which are hinged to permit access to said lamps.
 12. A lighting installation as defined in claim 11 wherein said lighting fixture includes: first means electrically conNecting the end terminals on said second end tube sections in common; second means for connecting the remaining end terminals in common; and, a reflector positioned below said connecting means and the adjacent ends of said tubes for reflecting through the open side of said center transverse channel the light emitted from said adjacent tube ends in a manner to provide generally uniform illumination along the entire length of said center channel section. 